What does it mean that Wicked Problems have no Stopping Rule?

I'm studying Design. One of the concepts is Wicked Problems.

I don't understand, re: Wicked Problems: No Stopping Rule

I looked up further and found: " You can tell when you’ve reached a solution with an ordinary problem. With a wicked problem, the search for solutions never stops."

Does that mean you don't know before you actually IMPLEMENT the solution?
(I.e., we don't know if the rocket will make it to the moon unless we launch it) or that we don't know even AFTER we implement it.

And if we continue searching AFTER we deploy the solution and test, why do we keep searching? Are we always looking for a better solution?